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Biomedical subjects

S Hirano

Publications and source records attributed to S Hirano.

At least 109 records · Page 6Linked to original sources
PubMed1999

Syk and paxillin are differentially phosphorylated following adhesion to the plastic substrate in rat alveolar macrophages.

Adhesion is associated with tyrosine phosphorylation in many types of cells. Although macrophages are known to adhere and phagocytose foreign particles, the signal transduction pathway of macrophages in response to adhesion to the foreign substrate has not been fully investigated. In the present study we investigated tyrosine-phosphorylated proteins and phosphorylation of paxillin in alveolar macrophages (AMs) following adhesion to a plastic substrate. Adhesion to a plastic dish resulted in tyrosine phosphorylation of a 68 000 MW protein, which was shown, by immunoprecipitation and immunoblotting in the present study, to be a rat Syk kinase. Treatment with erbstatin reduced both tyrosine phosphorylation of Syk and adherence of AMs, while treatment with cytochalasin B inhibited spreading of AMs but did not inhibit tyrosine phosphorylation of Syk. These results suggest that tyrosine phosphorylation of Syk plays an important role in adhesion of AMs to the plastic substrate, but not in AM spreading. Paxillin is known to be tyrosine phosphorylated following adhesion to the extracellular matrix in many types of cells. However, paxillin appeared to be serine/threonine phosphorylated rather than tyrosine phosphorylated following adhesion of AMs to the plastic substrate. Treatment with A23187 (a calcium ionophore), but not phorbol 12-myristate 13-acetate (PMA; a protein kinase C stimulator), induced tyrosine phosphorylation of Syk in non-adherent AMs. Treatment with either A23187 or PMA caused electromobility changes of paxillin that were mainly a result of serine/threonine phosphorylation. These results suggest that adhesion to the plastic substrate leads to two differently regulated events in AMs: tyrosine phosphorylation of Syk and serine/threonine phosphorylation of paxillin, both of which are probably mediated by an increase in intracellular calcium.

Animals↗
PubMed1999

Dorsoventral differential distribution of collagen type XIV around the spinal cord is regulated by the ectoderm.

Regional specification in the nervous system is a critical issue in nervous system morphogenesis. Along the dorsoventral axis of the spinal cord, ventral inductive signals of the notochord and floor plate, and dorsal ones of the epidermal ectoderm are essential. Collagen type XIV is uniquely distributed around the spinal cord with a gradient of dorsal high and ventral low at the early developmental stages of the chick embryo. In the present study it was found that collagen type XIV expression around the spinal cord was entirely regulated by the ectoderm and that even the ventralizing tissues, the notochord and floor plate, themselves could be influenced to express this molecule by the ectoderm.

Animals↗
PubMed1999

Personality disorder comorbidity in early-onset versus late-onset major depression in Japan.

This study explored the comorbidity of DSM-III-R personality disorders in early-onset versus late-onset major depression in Japan. The subjects were 117 consecutive outpatients with major depression, with 26 classified as having an early onset (first depressive episode at age 22 or earlier) and 91 classified as having a late onset (first depressive episode at age 23 or later). Personality disorders were assessed using the Structured Clinical Interview for DSM-III-R Personality Disorders after a 2-month antidepressant treatment. The results indicated that early-onset major depression was characterized by greater personality disorder comorbidity than late-onset major depression in Japan. Subjects with any one cluster A or B personality disorder were more prevalent in the early-onset group. In terms of each personality disorder, histrionic, narcissistic, and borderline patients were more prevalent, and the number of criteria met for schizotypal and cluster B personality disorders was significantly larger in early-onset major depression after corrections for age and gender. The results suggested that the higher prevalence of personality pathologies in early-onset major depression may reflect a higher likelihood to convert into bipolar disorders or a stronger impact of having experienced depressive episodes in young individuals. The possibility that the predisposing personality pathology may be different in early-onset and late-onset major depression is also discussed.

Adult↗
PubMed1999

Inhaled nitric oxide reduces tyrosine nitration after lipopolysaccharide instillation into lungs of rats.

Nitric oxide (NO) may either protect against or contribute to inflammatory lung injury. In this study we investigated whether inhalation of 20 ppm NO alters tyrosine nitration, and we assessed the degree of lung inflammation and edema in rats after lipopolysaccharide (LPS) instillation. The amount of nitrotyrosine relative to the total amount of tyrosine was measured in lung homogenates, and lung tissue sections were stained for nitrotyrosine and aminotyrosine (a reduced form of nitrotyrosine). Leukocytes in bronchoalveolar lavage fluid (BALF) were counted, and myeloperoxidase activity was measured in lung homogenate. Lung edema and inflammatory cell accumulation in lung tissue were estimated by extravascular lung water weight (EVLW) and extravascular dry lung weight (EVDW), respectively. LPS instillation caused increases in nitrotyrosine concentration and immunohistochemical staining of nitrotyrosine and aminotyrosine in the lungs. LPS instillation increased the BALF leukocyte count, myeloperoxidase activity in lung tissue, and both EVLW and EVDW. Inhalational exposure to 20 ppm NO induced nitrotyrosine and aminotyrosine formation only in bronchial epithelial cell surface of the lungs not instilled with LPS. NO inhalation reduced the increases in nitrotyrosine and aminotyrosine in LPS-instilled lung tissue as well as the leukocyte count in BALF and myeloperoxidase activity in lung tissue, but it did not significantly change EVLW or EVDW. Leukocyte depletion in LPS-instilled rats reduced interstitial inflammatory cells, which were stained with nitrotyrosine and aminotyrosine, and attenuated the nitrotyrosine staining of alveolar capillaries. These results suggest that inhalation of 20 ppm NO reduces leukocyte accumulation in the lungs and inhibits tyrosine nitration caused by LPS instillation.

Administration, Inhalation↗
PubMed1999

Anatomic study for posterior medialization thyroplasty.

To attain posterior medialization by thyroplasty type I, we simulated the surgery using 3 cadaveric larynges. Two approaches were applied to adduct the arytenoid cartilage: one involved compression of the vocal process, and the other, compression of the muscular process inward. The inner perichondrium was incised to reach the arytenoid cartilage from the framework. To compress the vocal process, a large silicone plug was required. In this method, there was some difficulty in compressing the vocal process precisely, and there was the risk of postoperative extrusion of the large plug. In contrast, the muscular process was more superficial relative to the framework, and it could be precisely compressed, resulting in sufficient posterior glottal closure. The silicone plug required for this procedure has a shallow depth that may provide the advantage of preventing postoperative extrusion. In conclusion, the compression of the muscular process is preferable for safely achieving posterior glottal closure.

Arytenoid Cartilage↗
PubMed1999

Synthesis and biological evaluation of 1,2,3,4-tetrahydroisoquinoline derivatives as potent and selective M2 muscarinic receptor antagonists.

A series of 1,2,3,4-tetrahydroisoquinoline derivatives containing the 5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one skeleton were prepared and evaluated for their in vitro binding affinities to muscarinic receptors and for antagonism of bradycardia in vivo. Among them, compound 3f had the highest affinity for M2 muscarinic receptors in the heart (pKi = 9.1) with low affinity for M3 muscarinic receptors in the submandibular gland. A structure-activity relationship (SAR) study suggested that the benzene ring fused piperidine and the alkyl linker chain length are crucially important for increased M2 affinity.

Animals↗
PubMed1999

[Three-dimensional reconstruction of functional brain images].

We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: 1) routine images by SPM, 2) three-dimensional static images, and 3) three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface model is the most common method of three-dimensional display. However, the volume rendering method may be more effective for imaging regions such as the brain.

Brain↗
PubMed1999

Experimental impression tray fabricated with a NiTi shape memory alloy plate.

A small experimental impression tray was fabricated with a NiTi shape memory alloy plate. After recovery of the shape memory effect, the upper rims of the tray holding the impression were opened to some extent, the resistance during removal of the model from the impression was significantly decreased compared to a commercially available tray and the tray before recovery of the shape memory effect. The pull-out force of the model from the impression was 23.5(0.2)N for the commercially available tray, 23.5(3.9)N for the experimental tray before recovery of the shape memory effect and 14.7(4.0)N after recovery of the shape memory effect (heated for 15 min at 70 degrees C). Therefore the tray should be useful in teeth fracture free modeling.

Dental Alloys↗
PubMed1999

Setting shrinkage and hygroscopic expansion of resin-modified glass-ionomer in experimental cylindrical cavities.

The effects of the C-value (bonded surface area/unbonded surface area) and the volume of the cavity on the volumetric dimensional changes [volumetric setting shrinkage (VSS) and volumetric hygroscopic expansion (VHE)] of a resin-modified glass-ionomer (RMGI) filled in experimental cylindrical cavities were evaluated. The VSS and the VHE rate decreased with increasing C-value. There was a high inverse regression between the cavity C-value and volumetric dimensional changes, but a low regression between cavity volume and volumetric dimensional changes. Therefore, it was thought that greater contraction stress would remain in high C-value cavities than low C-value cavities during the setting process. It was also confirmed that the volumetric dimensional changes of RMGI in cavity were influenced primarily by the cavity C-value.

Absorption↗
PubMed1999

[Dental treatment and oral health care on Tokashiki Island, Okinawa].

Okinawa Prefecture has been promoting dental treatment and oral health care in places where there are no dentists. The Ministry of Health and Welfare has been cooperating with eight dental colleges, including Tokyo Medical and Dental University, for promotion thereof since 1961. The 155th promotion was held on Tokashiki Island. The caries prevalence rate of the students on Tokashiki Island was relatively high compared with the average caries prevalence rate of the same age group throughout Japan, and most of the caries were thought to be due to too many soft drinks. Resin filling was the most popular treatment during this promotion. Severe periodontal disease was observed in middle-aged persons, but we could only perform initial periodontal treatment because of the limited treatment period. Complete or partial dentures were made or repaired for many elderly. The questionnaire study showed most of the denture wearers on Tokashiki Island were satisfied with their dentures, although many dentures did not fit, and the prescription was improved. The period of this promotion was too short to perform complete dental treatment and to prevent caries and periodontal disease, and primary prevention and higher dental hygiene education should be strengthened in no dentist areas like Tokashiki Island.

Adolescent↗
PubMed1999

[Magnetoencephalographic and electrocorticographic studies on the epileptogenic focus in a patient with Kojewnikow syndrome].

Partial motor seizures occur, followed after a variable interval by well-localized myoclonic jerks, in the patients with Kojewnikow syndrome, or epilepsia partialis continua. However, the epileptogenic focus remains to be established. We studied the epileptogenic focus of a 17-year-old boy with intractable Kojewnikow syndrome. Interictal EEG, ictal EEG, jerk-locked averaging, and ictal SPECT revealed a left central focus. A giant SEP indicated increased exitability of the primary sensory area. Magnetoencephalogram (MEG) and electrocorticogram identified the epileptogenic focus in the pre- and post-central cortex, indicating involvement of both the primary motor and sensory areas. Surgical treatment was successful. Thus, MEG proved to be the most accurate tool in the presurgical evaluation.

Adolescent↗
PubMed1999

[Sclerosing lipogranuloma of the scrotum: a case report].

We present a case of sclerosing lipogranuloma of the scrotum. A 42-year-old man who had complained of a painless intrascrotal mass of one week's duration visited our clinic. Physical examination revealed a symmetrical Y-shaped hard mass around the penile base in the scrotum. Laboratory examination showed no abnormal findings except for a 14.0% eosinophilia. Magnetic resonance imaging (MRI) with a surface coil showed an atypical mass at the penile base. Percutaneous needle biopsy under ultrasound guidance was performed and histopathological findings revealed lipogranuloma accompanied by infiltrating multinuclear giant cells, eosinocytes and lymphocytes. The tumor gradually disappeared during a 4-week administration of antibiotics and antiphlogistics. We have also reviewed 95 cases of sclerosing lipogranuloma of the scrotum in the Japanese literature.

Adult↗
PubMed1999

[Germinal matrix hemorrhage and hydrocephalus in premature infants].

An analysis of 25 preterm infants with grade 3 or 4 intraventricular hemorrhage and surgically treated progressive hydrocephalus was undertaken to assess mortality, cognitive outcome and motor deficit. All patients underwent surgery at the author's institute since 1981 and represented 4.7% of all intraventricular hemorrhage in premature infants. Surgical procedure was initial placement of a miniature Ommaya's reservoir and conversion to a ventriculoperitoneal shunt diversion. Overall, outcomes were achieved in 64.7% of ambulatory and improvement of cerebroventricular index on follow-up CT image from 0.68 +/- 0.36% to 0.36 +/- 0.31%. The presence of intraventricular hemorrhage continues to be a major problem in low birth weight infants whose rate survival continues to increase as the major improvements in perinatal medicine. We feel that miniature Ommaya's reservoir is quite helpful in the treatment of posthemorrhagic hydrocephalus in the preterm infant who prove refractory to aggressive conservative therapy.

Cerebral Hemorrhage↗
PubMed1999

[Computed assisted area measurement using CT scans: clinical application for craniosynostosis in children].

This paper describes a method for obtaining intracranial area measurements using CT scans with a software for quantitative analysis of tracing data. A Toshiba CT 1010 scanner was used (120 kv, 10 mm slice thickness) to examine 13 children before and after cranioplastic surgery for craniosynostosis. Using Scion Image (Scion Corporation) with Intuos tablet system (WACOM), the intracranial space was measured at approximately same scanning level. Our findings show that the reverse pi and bilateral canthal advancement procedures usually carried out are associated with increased intracranial area, 4.5 +/- 2.1% and 12.0 +/- 8.3%, respectively. This measurement method should be further modified to intracranial volume gain by several surgical procedures.

Craniosynostoses↗
PubMed1999

[Spinal lipoma in children: analysis of magnetic resonance image for upward displacement of medullary-conus on 44 consecutive surgical cases].

Medullary conus-untethering operation was conducted on 52 infants with spinal lipoma. Magnetic resonance (MR) image was used in order to evaluate the untethering results in 44 out of these 52 patients who could be followed-up after Osaka Medical Center & Research Institute for Maternal & Child Health was opened. Talking into account the changes in vertebral body during the growth period of infants, the authors studied the upward displacement of the conus-lipoma interface by four fractional MR sagittal image, using the vertebral body-intervertebral disc space as the baseline. Upward displacement was confirmed in 27 of 44 (61.4%). The mean, median and trimmed mean of upward displacement were 1.78 +/- 0.80, 2.0, 1.70 fractions, respectively. Sixteen (59.3%) were caudal type, 10 (37.0%) were transitional type and 1 (3.7%) was dorsal type. By type of spinal lipoma, upward displacement was observed in 16 of 23 caudal type patients (69.6%), 10 of 16 transitional type patients (62.5%) and 1 of 5 dorsal type patients (20%). While the rate of upward displacement was almost equal between the caudal and transitional type, that of dorsal type was lower. However, statistical analysis for the difference in population percentage of the three groups showed that significant difference existed only in the caudal type group.

Female↗
PubMed1998

Ultrahigh-vacuum reaction apparatus to study synchrotron-radiation-stimulated processes.

An ultrahigh-vacuum reaction apparatus to study synchrotron-radiation-stimulated processes has been constructed and placed on beamline 4B of the synchrotron radiation storage ring (UVSOR) at the Institute for Molecular Science. The apparatus is designed so that multiple synchrotron radiation processes such as etching and chemical vapour deposition can be carried out successively without breaking the high vacuum. It is equipped with IR reflection absorption spectroscopy (IRRAS) apparatus and reflective high-energy electron diffraction (RHEED) apparatus for in situ observations. The basic parameters of the apparatus including etching and deposition rates have been measured. IRRAS using buried metal layer substrates has been confirmed to be a very useful method of analyzing the reaction mechanisms of the synchrotron-radiation-stimulated processes.

Journal Article↗